Methods and compositions for drying coal

Abstract

The present disclosure provides methods, compositions and systems for drying coal fines.

1. A method of reducing the water associated with wet coal fines comprising contacting said wet coal fines with at least one water-collecting material, wherein at least a portion of the water present in the mixture becomes associated with the water-collecting material;
 following said contacting, separating at least a portion of the water-collecting material from said coal fines; 
 passing said portion of the water-collecting material through a heater to remove at least a portion of the water from said portion of the water-collecting material; and 
 reusing water-collecting material obtained from said passing step to reduce the water associated with wet coal fines; 
 wherein said water-collecting material comprises alumina. 
 
     
     
       2. The method of  claim 1 , wherein said water-collecting material is in the form of particles. 
     
     
       3. The method of  claim 2 , wherein said particles have an average diameter that is at least 1 mm, and less than about 10 mm. 
     
     
       4. The method of  claim 3 , where in said particles comprise greater than about 90% alumina by weight. 
     
     
       5. The method of  claim 1 , wherein said separation separating comprises size-based separation. 
     
     
       6. The method of  claim 1 , wherein, following the collection of water by the water-collecting material, the amount of water associated with the coal fines by weight is less than about 10%. 
     
     
       7. A composition comprising wet coal fines and at least one water-collecting material, wherein at least 25% of the water (by weight) in the composition is associated with the water-collecting material, wherein said water-collecting materials is in the form of particles with an average diameter greater than 1 mm and less than about 15 mm or an average diameter greater than about 4 mm and less than about 32 mm; and wherein said particles comprise greater than about 90% alumina by weight. 
     
     
       8. A system for removing water from wet coal fines comprising:
 a first location in which the wet coal fines are admixed with at least one water-collecting material to form an admixture of wet coal fines and said water-collecting material; 
 a second location where at least a portion of said water-collecting material is removed from said admixture; 
 a third location where at least a portion of the water is removed from the water-collecting material; and 
 a transporter for transporting at least a portion of the water-collecting material obtained from the third location so as to permit a portion of the water-collecting material obtained from the third location to be admixed with additional wet coal fines; 
 
       wherein said water-collecting material comprises alumina. 
     
     
       9. A system according to  claim 8 , wherein following the step of forming said admixture, at least 25% of the water (by weight) in the composition is associated with the water-collecting material. 
     
     
       10. A system according to  claim 9 , wherein the amount of water by weight that is associated with the water-collecting material is at least 45%. 
     
     
       11. A system according to  claim 8 , wherein said water-collecting material is in the form of particles. 
     
     
       12. A system according to  claim 11 , wherein said particles have an average diameter at least 1 mm. 
     
     
       13. A system according to  claim 12 , where in said particles comprise greater than about 95% alumina by weight.